Method of developing silver halide photosensitive material

ABSTRACT

A PHOTOGRAPHIC DEVELOPING PROCESS WHICH COMPRISES DEVELOPING AN EXPOSED LIGHT-SENSITIVE SILVER HALIDE EMULSION LAYER OF A PHOTOGRAPHIC MATERIAL WITH AN ALKALINE SOLUTION IN THE PRESENCE OF HYDROQUINONE AND A DERIVATIVE OF P-AMINO PHENOL HAVING THE GENERAL FORMULA:   1-(HO-),2-X,3-Y,4-(R1-N(-R2)-),6-Z-BENZENE   WHEREIN EACH OF R1, R2, X, Y, AND Z IS AN ALKYL GROUP CONTAINING 1 TO 4 CARBON ATOMS IS DISCLOSED.   ALSO DISCLOSED IS THE ABOVE COMPOUND AND THE METHOD OF PREPARATION.

Feb. 26, 1974 ATSUAKI ARA] ETAL 3,794,489

METHOD OF DEVELOPING SILVER HALIDE PHOTOSENSITIVE MATERIAL Filed Dec. 10. 1971 United States Patent 3,794,489 METHOD OF DEVELOPING SILVER HALIDE PHOTOSENSITIVE MATERIAL Atsuaki Arai, Mitsugu Tanaka, Kinji Ohkubo, Tatsuya Tajima, and Yoshinori Tsuchiya, Kanagawa, Japan, assignors to Fuji Photo Film Co., Ltd., Kanagawa, Japan Filed Dec. 10, 1971, Ser. No. 206,820 Claims priority, application Japan, Dec. 10, 1970, 45/109,869 Int. Cl. G03c 5/30 U.S. Cl. 96-66 R 18 Claims ABSTRACT OF THE DISCLOSURE A photographic developing process which comprises developing an exposed light-sensitive silver halide emulsion layer of a photographic material with an alkaline solution in the presence of hydroquinone and a derivative of p-amino-phenol having the general formula:

Y X B1 wherein each of R R X, Y, and Z is an alkyl group containing 1 to 4 carbon atoms is disclosed.

Also disclosed is the above compound and the method of preparation.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention relates to a method of developing a silver halide photosensitive material. More particularly, it has as an object additionally improving the developing activity of hydroquinone by the use of a developing agent comprising hydroquinone in combination with a specific type compound as hereinafter described.

(2) Prior art Photosensitive material has heretofore been prepared by coating a photosensitive silver halide emulsion on a substrate such as glass plate, paper, plastic film, etc., followed by drying the coated product. After the thus prepared photosensitive material has been exposed to light, it is developed in a developer liquid which is an alkaline aqueous solution containing a developing agent as its essential ingredient, thereafter the developed material is subjected to stopping, fixation and water-rinsing treatments in sequence.

However, since this series of treatment processes requires a fairly long period of time, a number of improvements have been proposed directed to shortening the processing time. For instance, one improved method includes high temperature processing, single-bath development and fixation, double bath stabilization treatment processes, etc. One of the currently employed methods for shortening the time of development comprises adding a developing agent into a silver halide emulsion layer and then treating the layer in a highly alkaline aqueous solution containing an alkali agent and other photographic additives such as antioxidants and retarders and the like. The characteristic feature of that method resides in enabling quick developing with a shortened developing reaction time which is due to the use of the highly increased pH of the processing liquid that can be only attained by the absence of a developing agent in the processing liquid without degrading its storability. The silver halide photosensitive material to be employed in that method includes silver chloride emulsions and silver chlorobromide emulsions having a low silver bromide content which has a high rate of developing reaction.

On the other hand, various attempts have been made to carry out similar quick processing even with silver chlorobromide emulsions having a high silver bromide content, pure silver bromide emulsions, and silver iodobromide emulsions, by adding to these emulsions a developing agent. However, each of these silver chlorobromide emulsions, pure silver bromide emulsions and silver iodobromide emulsions have slower developing reaction rate than silver chloride emulsions, so that it has not been possible to obtain satisfactorily desirable photographic characteristics by this treatment in a short period of time.

Meanwhile, it is well known in the art that excellent photographic characteristics, which have never been attained with the use of hydroquinone alone, can be obtained in the usual development process for silver halide photosensitive emulsion containing no developing agents, by using a developer liquid containing hydroquinone together with a developing agent having super additivity such as l-phenyl-3-pyrazolidone or N-methyl-p-aminophenol (PQ or MQ developer). In addition, it is disclosed in the specification of U.S. Pat. No. 2,751,279 that the rate of development is accelerated by the addition of 1-phenyl-3-pyrazolidone to a silver hydroquinone solution or MQ developer.

By utilizing these prior teachings, we have made an attempt to accelerate the quick development of silver chlorobromide emulsions, silver bromide emulsions, and silver iodobromide emulsions each of which contains a developing agent admixed therein. It was found, however, that the addition of these accelerators, i.e., 3-pyrazolidone, N-methyl-p-aminophenol, etc. to the emulsion is disadvantageous because these accelerator compounds are very likely to undergo oxidation which not only results in lowering the activity of the compound during the storage of the sample but also discolors or contaminates the substrate base.

It has also been reported that certain p-aminophenol derivatives such as compound (I), which is disclosed in U.S. Pat. 3,134,673 Gauguin et al., issued May 26, 1964, and compound (II), which is disclosed in the U.S. Pat. No. 3,265,499, have superior additive powers than the above-mentioned 1-pheny1-3-pyrazolidone and N-methyL p-aminophenol when used in combinations with hydroquinone.

We have made an attempt to improve the above drawbacks encountered when using the compound described in the above-mentioned U.S. patent, by adding the following compounds to a photographic emulsion,

wherein R is, for example, an alkyl group having 1 to 6 carbon atoms, R for example, methyl or ethyl group and X is a, for example, methyl, ethyl and alkoxyl group having 1 to 6 carbon atoms.

z-CIQ l I GHQ-CH2 wherein each of X and X. is, for example, a hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, an alkyl-amino group, etc.

However, the emulsion incorporated with these compounds is likely to generate fogging which leads to another disadvantage in that the developing speed appreciably decreases when trying to prevent the fogging by adding a known fog inhibitor.

We have now found that the aforesaid disadvantages can be obviated by the addition to a silver halide emulsion of a compound represented by the General Formula 111 in combination with hydroquinone, and also that excellent photographic characteristics can be obtainedby developing the photographic material with the use of a single hydroquinone developer. We have also discovered that an alkaline developer liquid containing the compound shown by the General Formula III and hydroquinone is an excellent photographic developing liquid.

/N CH wherein each of R and R is an alkyl group having 1 to 4 carbon atoms and each of X, Y and Z is an alkyl group having 1 to 4 carbon atoms.

(3) Objects of the invention An object of this invention is to improve the photographic characteristics in a conventional rapid developing process using a photographic paper, by adding the abovementioned compound of the General Formula III into a silver halide emulsion layer and/or adjacent layer such as a protective layer of an undercoat layer containing a developing agent therein.

A further object of this invention is to employ a compound of the General Formula III as an essential developing agent having super additivity when combined with hydroquinone for developing monochromic and color photography.

A still further object of this invention is to accelerate the developing speed upon usual developing treatment by adding the compound of the General Formula III into either one of an emulsion layer, a protective layer or an undercoating layer of silver halide photosensitive material containing no developing agent added therein.

Other objects will be apparent to those skilled in the art as the description of this invention proceeds.

BRIEF DESCRIPTION OF THE DRAWING The drawing illustrates the results obtained when the compounds disclosed in this inveniton are compared with known compounds of the prior art which are generally used to provide accelerated developing speed.

DESCRIPTION OF THE INVENTION The novel developing agent of the above General Formula III may be usually used in the form of stable salts such as hydrochloride or sulfate rather than in the form of free amine. More particularly the Compounds (III) identified hereinafter have proved to be very suitable for being applied in the process according to the present invention:

(1) 4-dimethyl amino-2,3,6-trimethyl phenol hydrochloride;

(2) 4-di-n-propylamino-2,3,6-trimethyl phenol hydrochloride; and

(3) 4-di-n-butylamino-2,3,6-trimethyl phenol sulfate.

These Compounds III are employed with hydroquinone in the process, material and/or alkaline solution of the process as follows:

The compound represented by the General Formula HI is effective for the combination with either pure silver chloride, silver chlorobromide, pure silver bromide or silver iodobromide, but an outstanding effect is attained when it is combined with silver chlorobromide, pure silver bromide or with silver iodobromide emulsions each of which is known to have a slow developing activity.

The developing agent to be used in combination with the compound of the General Formula III in accordance with the present invention is not limited to any specific types, but it is possible to use any compounds which are conventionally used as photographic developing agents having reducing activity. Examples of such developing agents include hydroquinone or its derivatives, catechol or its derivatives, ascorbic acid, etc.

The substrate to be used for supporting the silver halide photographic material may be any one of those materials so far as it can support a silver halide emulsion layer, and typically includes paper, plastic films, etc., which may be further provided with a baryta layer or an undercoating layer.

The silver halide emulsion to be used is intended to include silver halide photosensitive materials, and may contain gelatin or other synthetic resins such as poly (vinyl alcohol), poly (vinyl acetal), etc., as a binder.

Since the compound of the General Formula 3 is a novel compound, the following Examples A and B are given for illustration of the synthesis of the compound.

EXAMPLE A Synthesis of 4-dimethylamino 2,3,6 trirnethylphenol hydrochloride:

A 500 ml. autoclave was charged with 19 g. of 4-amino- 2,3,6-trimethylphenol, prepared in a process as disclosed in British Pat. 1,126,219, 27 ml. of a 37% Formalin, 1.5 g. of a 10% Pd-C and 200 ml. of ethanol and, after gaseous hydrogen was introduced thereinto to a pressure of 54 atms., the charge was stirred at room temperature for about 24 hours. The reaction mixture was filtered, the filtrate was distilled under reduced pressure to eliminate ethanol and the residue was distilled under a reduced pressure of 1 mm. Hg. The distillate was collected with the raising of the temperature of the oil bath to 150 C. and was dissolved in 500 ml. of diethyl ether. Into the solution was blown gaseous dry hydrogen chloride to obtain the end product in the form of white fine powdery crystals at a yield of 14.4 g. (53.3% of theoretical). The product was recrystallized from a mixed solution of ethanol and a small amount of a dilute aqueous hydrochloric acid to obtain colorless flaky crystals.

EXAMPLE B Synthesis of 4 diethylamino-2,3,6-trimethylphenol hydrochloride:

In a similar manner as taught in Example A, there was obtained an end product in the form of white powdery crystals at a yield of 13.0 g. (42.5% of theoretical) from 19 g. of 4-amino-2,3,6-trimethylphenol, 15 ml. of an aqueous acetaldehyde, 1.5 g. of a 10% Pd-C and 200 ml. of ethanol.

The present invention will be now illustrated in detail by the following examples.

EXAMPLE 1 To 400 cc. of a silver halide gelatin emulsion containing 50 g. of gelatin and 20 g. of a silver chlorobromide in which silver bromide amounted to 60 mol percent there were added, other than necessary film hardener and coating assistants, one or more developing agents as listed in the following Table 1 to form a coating liquid. A photographic baryta paper of a weight of g./m. was coated with the coating liquid and then, before drying of the emulsion layer, after setting of the emulsion layer, with a solution consisting of 20* g. of gelatin, 6 cc. of a 6% methanol solution of saponin and 1 liter of water to form a protective coating layer and dried to prepare a specimen A to H. The printing paper thus obtained was exposed through an optical wedge (stepped wedge) and developed with an activation solution of the following composition.

Activating solution: G. Anhydrous sodium sulfite 45 Sodium hydroxide 48 Potassium bromide 1.3

Water to form 1,000 cc. solution.

Sensitometric characteristics obtained after stabilization by a stabilizing solution containing ammonium thiocyanate (NH SCN) were summarized in the following Table 1.

TABLE 1 Sensltometry Relative Maximum Specimen developing agent sensitivity density Gamma A. Hydroquinone, g. (control). 1.00 1. O2 1. 40 B. Hydroquinone, 10 g. plus 1- phenyl-3-pyrazolidone, 0.50

1.60 1. 31 1.83 C. Hydroquinone, 10 g. plus methol, 0.53 g 1. 49 1. 25 1. 93 D. Hydroquinone, 10 g. plus 4- diethylaminophenol hydrochloride, 0.63 g 1. 51 1.27 1. 85 E. Hydroquinone, 10 g. plus 4- diethylamino 2 methyl phenol hydrochloride, 0.65

1.73 1.45 1.98 F. Hydroquinone 10 g. plus 1- (lii5-diglethy hydl rloxiyeny -pyrro ne y ohloride, 0.70 g 1. 61 1. 34 1. 84 G. Hydroquinone, 10 g. plus 2,3,-

G-trimeth yl-p aminophenol hydrochloride, 0.54 g 1. 58 1. 40 1. 86 H. Hydroquinone, 10 g. plus 4- dimethylamino 2,3,6 tri methylphenol hydrochloride, 0.65 g l. 82 1. 65 2. 22

It will be noted from the above Table 1 that the specimen H incorporating therein a compound of the present invention is superior to the other specimens as indicated by a remarkably high sensitivity, maximum density, and gamma.

EXAMPLE 2 To 400 cc. of a silver halide gelatin emulsion containing 50 g. of gelatin and 20 g. of silver iodobromide in which silver iodide amounted to 1.5 mol percent there were added necessary film hardeners and coating assistants to prepare a coating solution. A photographic baryta paper of a weight of 150 g./m. was coated with the coating solution and, while the emulsion layer was in a set but undried state, with a coating solution consisting of 30 g. of hydroquinone and 1.4 g. of 4-dimethylamino-2,3,6-

trimethylphenol hydrochloride as developing agents, 2 g. I, of sodium benzenesulfinate as an antioxidant for develop- I EXAMPLE 3 A photographic baryta paper of a weight of 150 g./m. was coated with a coating solution consisting of 50 g. of gelatin, 35 g. of hydroquinone, 1.5 g. of 4-dimethylamino- 2,3,6-trimethylphenol hydrochloride, 2 g. of sodium benzenesulfinate as antioxidant for hydroquinone, 2 cc. of 30% formalin, 1.0 g. of a phosphorescent whitening agent, Blankophor -BUP supplied by Bayer A. G., and 1 liter of water. Thereover was applied a coating solution prepared by adding necessary film hardeners and coating assistants to 400 cc. of a silver halide emulsion containing 50 g. of gelatin and 20 g. of a silver chlorobromide in which silver bromide amounted to 60 mol percent and then, while the emulsion layer was in a set state but before dry, was applied a solution consisting of 20 g. of gelatin, 6 cc. of a 6% methanol solution of saponin and 1 liter of Water to form a protective coating layer. For comparison, a specimen of printing paper containing no 4-dimethylamino-2,3,6 trimethylphenol hydrochloride therein was prepared in the similar procedure.

When both specimens were processed in the similar manner as in Example 1, the specimen containing the 4- dimethyl-amino-2,3,6 trimethylphenol hydrochloride in its subbing layer exhibited excellent sensitometric characteristics corresponding to higher sensitivity, maximum density and gamma than those of the comparative specimen.

EXAMPLE 4 A coating solution was prepared by adding necessary film hardeners and coating assistants to 400 cc. of a silver halide gelatin emulsion containing 50 g. of gelatin and 20 g. of a silver chlorobromide in which silver bromide amounted to 50 mol percent. The coating solution was applied to a photographic baryta paper of a weight of 150 g./m. to form a printing paper.

The printing paper thus obtained was exposed in a fixed quantity of exposure and developed with a developing solution of the following composition. Changes in black ening density with developing time were plotted in the FIG. 1 in the accompanying drawing, in which the curves 1 to 5 corresponded to a sole or combined developing agent as indicated in the following table.

Water added to make a 1,000 cc. solution. 1 mole per mole of hydroquinone.

It would be understood by comparison of the curves shown in the FIG. 1 that the compound of the present invention has a very high super additivity with respect to developing power.

EXAMPLE 5 To a silver halide emulsion containing g. of gelatin and 40 g. of a silver chlorobromide (A'gBr 60 mol percent) per kg. there were added 30 g. of hydroquinone per kg. of emulsion and other necessary additives and the emulsion was applied to a photographic baryta paper of a weight of g./m. and dried. The printing paper thus produced was exposed through an optical wedge and developed for 4 seconds in an activating solution as indieated in Example 1 or an activation solution obtained by adding to the activation solution of Example 1 0.9 g., per liter of the solution, of the compound of Example A and, after stabilization with a stabilizing solution contain- TABLE 2.ACTIVATING SOLUTION, RELATIVE SENSITIV- IIY, MAXIMUM DENSITY AND CONTRAST Containing the compound of example A 1 51 Not containing the compound of example A.

It should be noticed that the compound obtained in Example A remarkably accelerates development by hydroquinone.

EXAMPLE 6 The silver halide emulsion as employed in Example 5 was added with 1.8 g., per kg. of emulsion, of the compound obtained in Example A and other required additives, and applied to a photographic baryta paper of a weight of 150 g./m. and dried. The printing paper thus obtained and a printing paper prepared by using the same emulsion except for not containing the compound of Example A were exposed through an optical wedge, developed for 4 seconds in an activating solution prepared by adding g. of hydroquinone to per 1 liter of the activating solution as employed in Example 1, stabilized with a stabilizing solution containing ammonium thiocyanate and subjected to a sensitometry for determination of relative sensitivity, maximum density and contrast. The results were as summarized in the following Table 3.

TABLE 3.PRINTING PAPER, RELATIVE SENSITIVITY, MAXIMUM DENSITY AND CONTRAST Containing the compound obtained in example A 13. 00 1. 20 1. 56 Not containing the compound obtained in example A 1. 00 0. 68 0.

It will be seen that the compound prepared in Example A accelerated the development with hydroquinone.

As fully ilustrated above, the process of the present invention is applicable not only to silver halide photosensitive materials containing a developing agent in an emulsion layer but also to more conventional ones containing no developing agents in the emulsion layer, e.g., photographing or printing, was to obtain a good result.

What is claimed is:

1. A photographic developing process which comprises developing an exposed light-sensitive silver halide emulsion layer of a photographic material with an alkaline solution in the presence of hydroquinone and a derivative of p-amino-phenol having the general formula:

wherein each of R R X, Y and Z is an alkyl group containing 1 to 4 carbon atoms, said hydroquinone and said derivative of p-amino-phenol being present in said emulsion layer, a layer adjacent to said emulsion layer or in said alkaline solution.

2. The process according to claim 1, wherein each of said X, Y and Z is a methyl group.

3. A photographic developing process according to claim 1, wherein said hydroquinone is incorporated in said emulsion layer, and said derivative is incorporated in said alkalne solution.

4. A photographic developing process according to claim 1, wherein said hydroquinone is incorporated in a layer adjacent to said emulsion layer and said derivative is incorporated in said alkaline solution.

-5. A photographic developing process according to claim 1, wherein said hydroquinone is incorporated in'said alkaline solution, and said derivative is incorporated in said layer.

6. A photographic developing process according to claim 1, wherein said hydroquinone is incorporated in said alkaline solution, and said derivative is incorporated in a layer adjacent said emulsion layer.

7. A photographic developing process according to claim 1, wherein said hydroquinone and said derivative are incorporated in said emulsion layer.

8. A photographic developing process according to claim 1, wherein said hydroquinone and said derivative are incorporated in a layer adjacent said emulsion layer.

9. A photographic developing process according to claim 1, wherein said hydroquinone and said derivative are incorporated in said alkaline solution.

10. A photographic developing process according to claim 1, wherein said hydroquinone is incorporated in said emulsion layer in an amount of from 5 to 500 grams per mole of light-sensitive silver halide.

11. A photographic developing process according to claim 1, wherein said derivative is present in said emulsion layer in an amount of from 0.05 to 50 grams per mole of light-sensitive silver halide.

12. A photographic developing process according to claim 1, wherein said hydroquinone is present in said alkaline solution in an amount of from 1 to 70 grams per liter of said alkaline solution.

13. A photographic developing process according to claim 1, wherein said derivative is present in said alkaline solution in an amount of from 0.01 to 20 grams per liter of said alkaline solution.

14. A photographic developing process according to claim 1, wherein said derivative is selected from the group consisting of 4-dimethylamino-2,3,6-trimethyl phenol hydrochloride, 4-di-n-propylamino 2,3,6 trimethyl phenol sulfate, and 4-di-n-butylamino 2,3,6 trimethyl phenol hydrochloride.

15. A photographic material having at least one lightsensitive silver halide emulsion layer, which contains hydroquinone and a derivative of p-aminophenol having the general formula:

wherein each of R R X, Y and Z is an alkyl group containing 1 to 4 carbon atoms.

16. The photographic material according to claim 15, wherein said X, Y and Z are methyl.

17. An alkaline solution for photographic development which contains a derivative of p-aminophenol having the general formula:

Y X R1\ I /N OH R1 i wherein each of R R X, Y and Z is an alkyl group containing 1 to 4 carbon atoms.

18. The alkaline solution according to claim 17, wherein said X, Y and Z is methyl.

References Cited UNITED STATES PATENTS 3,134,673 5/1964 Ganguin et al 96-66 R 3,257,207 6/1966 Green 9666 R 3,600,176 8/1971 Haist et al 96-66 R NORMAN G. TOROHIN, Primary Examiner M. F. KELLEY, Assistant Examiner US. Cl. X.R. 96-66.3 

